Jia Guo

Imperial College London | Imperial · Mechanical Engineering

A comprehensive understanding of aging mechanisms and degradation diagnosis under fast charging in battery electric vehicles is needed. However, there is a lack of tools to capture both macroscopic and microscopic parameters, still focusing on experiment results analysis. To get a comprehensive degradation insight for improved service life, this st...

The environmentally-friendly and efficient separation of cathode materials from aluminum (Al) foil is crucial in the recycling process of spent lithium-ion batteries (LIBs) for production of new ones. Here we report a new strategy for such separation. The strategy is based on the combination of a newly-developed green deep eutectic solvent (DES) as...

The key to advancing lithium‐ion battery (LIB) technology, particularly with respect to the optimization of cycling protocols, is to obtain comprehensive and in‐depth understanding of the dynamic electrochemical processes during battery operation. This work shows that pulse current (PC) charging substantially enhances the cycle stability of commerc...

The recycling and reutilization of spent lithium-ion batteries (LIBs) have become an important measure to alleviate problems like resource scarcity and environmental pollution. Although some progress has been made, battery recycling technology still faces challenges in terms of efficiency, effectiveness and environmental sustainability. This review...

Loss of Li-ions, which results in capacity loss, mainly occurs on the negative electrode in the form of Li plating or a surface film. Quantifying the loss of lithium in graphite anode is essential for studies such as waste battery recycling, lithium plating on negative electrodes, and interfacial film composition, which can guide the manufacturing...

The increasing growth of the second-hand electric vehicle market demands reliable methods for evaluating the state of health of deployed electric vehicle batteries. Among these methods, incremental capacity analysis is a commonly used technique for state of health evaluation via the quantification of degradation modes. While the optimal conditions...

Fast charging is considered a promising protocol for raising the charging efficiency of electric vehicles. However, high currents applied to Lithium-ion (Li-ion) batteries inevitably accelerate the degradation and shorten their lifetime. This work designs a multi-step fast-charging method to extend the lifetime of LiNi0.5Co0.2Mn0.3O2 (NMC)/graphite...

Lithium-ion battery aging mechanism analysis and health prognostics are of great significance for a smart battery management system to ensure safe and optimal use of the battery system. This paper provides a comprehensive review of aging mechanisms and the state-of-the-art health prognostic methods and summarizes the main challenges and research pr...

Biomass carbon materials with high theoretical specific capacity, low cost and pollution-free, play an essential role in secondary batteries as anode materials or modified substrates. This review classifies biomass based on its resource and composition and introduces the application of biomass raw fibers, biomass extracts, biomass synthetic fibers,...

Lithium-ion batteries (LIBs) are widely used in modern society. Since LIBs represent a substantial fraction and sometimes even majority of the device cost, extending the lifetime of LIBs and understanding their degradation mechanisms draw an increasing attention. Graphite, commonly used as the negative electrode in LIBs, suffers from two main degra...

Lithium-ion batteries have good performance and environmentally friendly characteristics, so they have great potential. However, lithium-ion batteries will age to varying degrees during use, and the process is irreversible. There are many aging mechanisms of lithium batteries. In order to better verify the internal changes of lithium batteries when...

Many factors affect the degradation behavior of lithium-ion (Li-ion) batteries and one of these is the depth of discharge (DOD). As Li-ion batteries are used, a reasonable DOD can not only extend their service life (by reducing the degradation rate) but can also reduce the frequency of the re-charging. Therefore, to investigate and clarify the effe...

A capacity increase is often observed in the early stage of Li-ion battery cycling. This study explores the phenomena involved in the capacity increase from the full cell, electrodes, and materials perspective through a combination of non-destructive diagnostic methods in a full cell and post-mortem analysis in a coin cell. The results show an incr...

Facing increasingly severe climate change, countries and regions around the world are actively promoting the electrification of the transportation sector and encouraging the use of electric vehicles (EVs) to replace traditional internal combustion engine vehicles (ICEVs). However, the consumption of energy, resources, and power during battery produ...

Constant current charging and discharging is widely used for nowadays commercial Lithium (Li) ion batteries (LIBs) in applications of portable electronic devices and electric vehicles. However, the main battery degradation...

Understanding the aging mechanism for lithium-ion batteries (LiBs) is crucial for optimizing the battery operation in real-life applications. This article gives a systematic description of the LiBs aging in real-life electric vehicle (EV) applications. First, the characteristics of the common EVs and the lithium-ion chemistries used in these applic...

The spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is an attractive high-voltage cathode material for commercial lithium-ion batteries because of its high energy density and low cost. However, surface side reactions and Mn dissolution during the cycling process damage the electrochemical performances of the material, especially at high rates. In this paper, the...

The spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) has received much attention as a cathode material in high energy density lithium-ion battery thanks to its high working voltage. It is recognized that its interface instability issues, especially for the Fd-3m phase with superior conductivity, Co 3 O 4 is employed as an interface coating to stabilize the surfac...

LiNi 0.5 Mn 1.5 O 4 (LNMO) is a promising cathode material for lithium-ion batteries due to its high discharge voltage, low cost, environmental friendliness, and high energy density. To enhance the electrochemical performance of LNMO, Cd is innovatively employed as a modifying agent. Structural and morphological characterizations confirm that CdO i...

SiO 2-modified LiMn 2 O 4 materials were synthesized by the electrostatic attraction forces with the followed heat treatment. The surface morphology, structure, and electrochemical performance were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), CV, and electrochemical impedance spectroscopies (EIS), respectively. SEM...